Answer:
Explanation:
wave length of light λ = 623 x 10⁻⁹ m .
Distance of screen D = 76.5 x 10⁻² m
width of slit = d
Distance on the screen between the second order minimum and the central maximum = 2 λ D / d
1.11 x 10⁻² = (2 x 623 x 10⁻⁹ x 76.5 x 10⁻² )/ d
d = ( 2 x 623 x 10⁻⁹ x 76.5 x 10⁻²) / 1.11 x 10⁻²
= 85872.97 x 10⁻⁹
= 85.87297 x 10⁻⁶
= 85.87 μm
width a of the slit is = 85.87 μm
Answer:

Explanation:
Given data
Mass m=67.0 kg
Final Speed vf=8.00 m/s
Initial Speed vi=2.00 m/s
Distance d=25.0 m
Force F=30.0 N
From work-energy theorem we know that the work done equals the change in kinetic energy
W=ΔK=Kf-Ki=1/2mvf²-1/2mvi²
And

So

and we know that the force the sprinter exerted Fsprinter the force of the headwind Fwind=30.0N
So
Yes that's a true statement. That's why grandmother put a hot water bottle to warm up her bed, and not a hot bar of steel or lead.